I keep reading about mattress toppers and I'm obviously missing something.
I have only ever used a mattress on its own, currently an Ikea foam mattress.
I have slept on two mattresses (realising only now that one was a mattress topper) in a friend's house but found it very uncomfortable (the sides kept partly curling up around me and it kept moving).
What am I missing? Does everyone have them? What is the difference between a topper and a mattress protector?